Colored image and process of producing the same



'ored Images and Processes of Same, of which thefollowingis a ful-l,clear,

-UNITED STATES PATENT O FFlCE.

J'OHN I. CRAIBTREE, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAKCOMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW'YORK. I

COLORED nines AND rnoorss or PRODUCING No -Drawing To all whom it mayconcern: r Be it'known that 1 JOHN I. QRABTREE, a subject of the King ofGreat Britain, re-

siding at Rochester, in the county of Monroe and State'ofNew York, haveinvented certain new and useful. Improvements in C01 Producing the andexact specification.

y invention. relates to co raphic images and the production;

hereof.

ify the image bfaphotograiphic "picture. se f that a dye-Will beadsorbedthereon fin cor-t respondence with the. original image, 1 thus;

giving a colored imagehaving approxi-f mately thesameform and gradationas the original picture. The inorganic part of such colored picture -maybe further treated .or removed. Flat or even tones may be simir larlychanged into colored tints suitablefor light'filters or generallight-modifying purposes. A flat or even tone'in the picture being butthe image of an object having a flat or even tone.- Ishall use the wordgenerically to include flattones as the more usual graded images.

The objects of my invention are to g well as will yield pictures-havinggood gradation,

that will not injure or impair the wearing. qualities of the product,that will producef Since images made up of silver particles;

suspended. '1Il gelatin are most commonly met with -in photographicpractice, I.will

describe, as an example of my invention, its

application to a silver image. Generally these results, carry out such apro s nd'zjg wy md run SAME.

Specification of Letters llatent. Patented Sept. 6,1921. Applicationfiled May 2, 1919. Serial No. 294,343.

stated, I treat the original, a primary image,-

in such a bath orbaths that/1t is converted danting dyes, "esp eci allyacid dyes of' the al1Za Il11 series: 'Themethods which will be convertedinto acomplex cyanid of silver and iron. In my pre erred process this Vgsalt is silver ferricyanld, but by the use of ore particularly itrelates rtothe mbtdant f 111g of y nto in 'g n c' cb pb li hi. may bedispersed or distributed through ai.

other baths silver ferro' yanid may be obtain'ed. This image is thenconverted .into

one'of -a. complexcyanid of iron and this suitable transparent ediu inthe fform of images. I For examp'laf-lifiayfadd' toor in-turhinto ironhydroxid This last is a transparent colloidal image and I is capable ofadsorbing or .mordanting dyes, and If .into an iron salt, which iscapable of mor preferred process. Algela'tin film in which a silverphotographic image is present'f'is bleached. in the following bath atF.,

for about two minutes, whereby the silver is converted into OHCDf silverferricyanid :q Potassium ferricyanid r uui'l .2igrams. Potassiumpermanganate .2 grams.

to; .4 C el v 1 Instead of theabove bleaching the hromic acid (10%...After being;ble ed g ln' the, above bath .hefilm is waslieforgabouta' minute in water 'andathen "'nmiersed' the] followingsolution whichf'i'conv rts the }s'ilver ferricy- 'anid iniage into ablue image' ofa' complex cyanid of iron-together withsilver chlorid:

Ferrous sulfate 15 grams. Hydrochloric acid ,5 cc. I Water .to ,.100.cc.

-The'ab0ve mentioned'bath also has theeffeet that itdissolves a littlemanganese stain (manganese dioxid) which was produced'by the first namedbleaching bath.

' After rinsing in water, the film is .now immersed ina 35% solution ofsodium thiosulfate for about a minute, so as to remove the is againrinsed and then immersed in a 1% solution of sodium carbonate or ofsodium or potasseum hydroxid. The action of this last named bath is toconvert theblue image to a faint yellow image of iron hydroxid.

The film containing this image is now placed in the dye solution, and Ihave found that many dyes, particularly acid dyes of the alizarinseries, will be mordanted to the image. The dye bath is composed of a 2%solution of the dye to which acetic acid or ammonia may be added. Thefollowing dyes are noted as giving typically good results.

Alizarin red S Alizarin orange Alizarin yellow 3 G Alizarin brownAnthracene blue When the bath contains 2% ammonia it gives the bestresults'with the above orange and yellow dyes. Ali'zarin red gives thebest result when the bath contains 12% .acetic acid. The temperature ofthe bath may be varied within certain limits, butit is primarily a coldbath in which the gelatin does not soften. The usual workingtemperatures would be F. After having been dyed the film is washed forabout -a minute to remove the excess dye, and it has been found thatprolonged washing and exposure to light does not affect the dye tones.

It is possible to obtain a pure dye image after the dye is thusmordante'd by removing the iron hydroxid with a suitable solvent; andfor this purpose I find a 2 per cent. solution of oxalic acidsatisfactory. There is left avery transparent dye image. With some dyesit is found. that the color of the remaining image is at first somewhataltered, but it is restored to the proper shade by being submitted torunning water for a short time.

In place of the bleaching bath first men- I tioned, the film containinga silver image may 45 be submittedto the following bath:

Potassium ferricyanid 10,000 grams. Ammonia (concentrated .89) 2 liters.200 liters.

silver ferroeyanid. It is then washed and may be treated with the acidferrous sulfate bath above mentioned, or with the following bath: aFerric ammonium sulfate 2000 grams. Potassium bromid 1000 grams.Hydrochloric acid (concentrated) 400 cc. Water to 200 liters.

In either case it is followed by the sodium thiosulfate and sodiumcarbonate baths above mentioned.

Still a third method of toning is to submit the silver image-to thefollowing bath or a similar one containing ferric ferricyanid insolution:

Potassium bichromate 5 grams. Ferric ammonium sulfate 250 grams. 70Oxalic acid 600 grams. Potassium ferricyanid 200grams. Ammonium alum1000 grams.- Hydrochloric acid (10%) 200 cc. -VVaterto 200 liters.

The image resulting from this bath is presumably one of unchangedsilver, silver ferrocyanid and ferric ferrocyanid. The unchanged silverand silver ferrocyanid are removed in a bathof potassium ferricyanid andsodium thios'ulfate (the well known Farmers reducer). The remaining blueimage may then be converted into an iron hydroxid image by a bath ofsodium carbonate, causticsoda, or" the like.

While the desired results may be obtained by following the processes asindicated above without a knowledge of the chemistry in volved, it maybeof interestv to note the probable reactions which occur. The reactionbetween ferrous sulphate and hydrochloric acid in the bath containingthem results inthe formation of ferrous chlorid. When the silverferricyanid image-,obtained by the first bath, is submitted to the acidferrous sulfate bath it is presumed that the reaction involved is givenby the following equation:

A The silver chlorid thus obtained is removed into hypo and theaction'of the sodium carbonate bath is presumed to be as follows:

It may be noted, however, that it is very questionable whether theferrous ferricyanid image obtained is a permanent one, as it is Hethought highly probable that the oxygen present in the wash wateroxidizes it into the ferric condition, so that the image is either onleof ferric ferrocyanid or one of the mixed sa ts.

e If the silver ferrocyanid image is first obtained,'the acid ferroussulfate bath in the presence of oxygen converts this to ferricferrocyanid and silver chlorid.

When, however, the silver image is trans-- 0 formed directly into thecomplex cyanid of iron image, the reaction involved is sup posed to beas follows:

It is understood that in place of sodium carbonate other bathscontaining hydroxyl ions may be used, in particular-solutions of any ofthe carbonated or caustic alkalis of 1 0 the alkali elements, lithium,sodium, potassium, and the radical ammonium. Other baths containingferrous ions tutedfor the acid ferrous sulfate bath.

The resulting image of colloidal iron hydroxid is transparent, and-theslight color present does not affect the dye image disadvantageously.The process which I have outlined as preferred is advantageous in that afilm is not submitted to any bath which tends the gelatin, by virtue ofa combination of the gelatin and iron. The ferrous ions do not appear tohave this efiect,where as the ferric ions which are present in thosebaths which contain a ferric salt have a mordantingeffeet and there is atendency for the dye to produce stained highlights in the dyed image. vI. Y The resulting colored film was found to be unimpaired in wearingquality, and, by attending to manipulate details given hereinabove,effects can be duplicated with certainty. The image is durable onprolonged exposure, either to water' or-light.-" Since the saltsresulting in each re-action are formed substantially in correspondenceor proportiontothe original image and since the dye is adsorbedsubstantiallylim proportion to the mordanting salt, the dyed image willhave a gradation similar to that of the original image.

While I have outlined above the preferred methods of carrying out thisprocess, it is understood that many changes may be'made and theproportions of ingredients may be varied within certain limits, and suchchanges are contemplated as being within the scope of my invention asdefined by the following claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. The process of producing a colored image from a photographic image,which cons'ists in replacing at least a part of the originalphotographic image by an iron toned image and mordanting a suitable dyeto the toned, image. I

2. The process o'f producinga'colored image from a silver photographicimage, whic l consists in replacing at least a part of the' silver imageby an image of an iron salt and I in treating said image with a suitabledye until sufiicient dye is mordanted thereby-to produce a coloredimage. p

. 3. The process of producing a colored image in: gelatin from a silverphotographic image, which consists in replacing the si ver image byanironhydrom'd image and. in

mordanting a dye the iron hydroxid tim age. z I

4. The producing a transparent colored 'ima'ge in gelatinfromajsilverphotographic image, which con's'istsimtransmay be substitoabnormally tan or harden graphic image in a forming the silver imageinto a colloidal iron hydroxid image and in mordanting theron an aciddye.

5. The process of producing a transparent colored image in gelatin froma silver photographic image, which consists in replacing at least. apart of the silver-image by a colloidal iron hydroxid image and inmordanting thereon at normal temperatures'an acid'dye of the alizarinseries.

6. The process of producing a colored im age in gelatin from a silverphotographic image, which consists in transforming the. silver imageinto an'image of a complex cyanid of silver and iron, transforming thisimage into one of a complex cyanid of iron, and then transforming thisimage into one ofiron hydroxid, and mordanting a dye upon the ironhydroxid. image.

7. The process of producing a mordanted dye image from a silverphotographicimage that comprises replacing at least a part of thesilver'image by an image of a complex cyanid of silver and iron,replacing at least a part of this image by one of a complex cyanid ofiron, and bathing this in a solutlon of one of the carbonated or causticalkalis of the alkali metals including ammonium, and then bathing theresultant image in a suitable dye.

8. The method of producing a transparent mordanted dye image from asilver photographic image in a gelatin film that comprises thetransforming of the silver image into a silver ferricyanid image, thenbathing it first in a solution containing ferrous ions,-and then in asolution containing hydroxyl ions and finally in an acid dye of thealizarin'series. 1

9. 'The process of producing a transparent 105 mordanted dye image froma silver photogelatin film, which process comprises bathing the film ina solution of potassium ferricyanid and an oxidizmg agent, then in anacid solution of ferrous sulfate, then in a solution of sodiumthiosulfate and then in a solution containing hydroxyl ions, whereby animage of colloidal iron hydroxid is obtained, and then' bathing the filminan acid dye of theflalizarin 115 series at a temperature less than F;10. The process ofproducing ina gelatin film a transparent mordanted dyeimage from 'a silver photographic imageywhi'ch comprises submitting thefilm containing the 120 silver image-to"abath containing potassiumferricyanid and an: oxidizing agent, then submitting it to a bathcontaining ferrous ions, then bathing it in a solution of sodiumthiosulfate,' a'nd then in a solutio 'contain- 125 ing hydroxylv 'ionsfwhich transforms the image into one of colloidal iron hydroxid, and then'mordanting an acid 'dye to the iron hydroxid image. I

11. Theprocess of producing a dye image 180 photographic image,

- parent dye image in gelatinfrom a silver photographic image, whichconsistsin replacing at least a part of the silver image byan image ofcolloidal iron liydroxid, treating-this image with a suitable acid dyeuntil sufficient dye is mordanted thereby .to

produce a colored image and then dissolving the iron hydroxld in asolution of oxalic acid, leaving a dye image.

14. The method of transforming a silver photographic image into an. ironhydroxid image, which consists of submitting it successively to bathsthat transform it into a complex cyanid of silver and iron, then into acomplex cyanid of iron and then into iron hydroxid.

15. The method of transforming a silver photographic image in gelatininto a transparent colloidal iron hydroxid image capable of mordantingdyes that consists in submitting the silver image to a solution ofpotassium ferricyanid and an oxidizing agent, then to an acid solutionof ferrous sulfate, thento a solution of sodium thiosulfate and finallyto a solution containing hydroxyl ions. 1

' 16. The method of transforming a silver photographic image into acolloidal iron hydroxid image, which consists in transforming it firstinto a silver ferricyanid image, then bathing ing ferrous ions, andthentransforming the resultant image into one of iron hydroxid.

17. A colored photograph comprising a dye image that has been mordantedupon an iron toned image. v

'18. A colored photographic image consisting of an iron toned andmordant dyed image. 19. A colored photograph comprising a colloid layercontaining an iron toned image and combined therewith a selectivelymordant dyedimage.

20. An article of manufacture comprising -a gelatin film. containing animage composed of anacid dye droxid. Y I

. 21. An article of manufacture comprising mordanted upon iron byagelatin film containing a transparent pho- 7' it in asolutioncontaintographic image. of colloidal iron hydroxid havingmordanted thereto an acid dye of the alizarin series.

day df April'191 9.

' JOHN I. CRABTREE.

Si ned at Rochester, New York, this 30th I

